Production of filamentary materials



Patented Se t. 19,1944 H NIT D STATES PATENT PRODUCTION or may Albert CharlesChibna-li, Totnes, Devon, and Kenneth Bailey, Cambridge, England,

said Chlbnali and- Leeds, Englandassls'nors to William. Thomas Astbury,

No Drawing. Application Mil-roll 12, 1941, Serial In Great Britain, Australia,

Greece, and India October 22, 1935' 29 Claims.

This invention relates to production oi filamental-y materials; and it comprises a method '0! making new and usefulfilamentary materials,

including filaments, fibers, threads, bristles, films.

and the like, irom'modified vegetable globulins, and particularly the oil seed globulins, wherein the selected globulin, such as the arachin andnarachin of peanuts, is dispersed in an aqueous solution of-urea or other suitable organic nitrogencompound giving a thin liquid, the thin dispersion. is purified and a'gedto increase its vistofore from certain other proteins, notably ca-. sein' and silk waste, by wet-spinning viscous solutions or these proteins. However, the filaments produced from the oil seed globulins in accordance withthe present invention are or. better quality than. those produced from animal proteins such as casein and silk waste; andtheraw materials for producing these oil seed globulins cosity to a point allowing extrusioni is extruded into a medium adapted to counteract the dispersive efiect oi the organic nitrogen compound and produce a solid, the olidified extrusion product is collected, advantageously under tension, and is hardened by chemical treatment; and it also comprises'the new and useful filamentary materials composed ot'modified vegetable globulins and obtainable in the manner described;

all as more fully hereinafter set forth and as claimed. f

. In another and copending application Serial No. 104,338, filed October 8, 1936, whereof the present application is a continuation-in-part, aredescribed and claimed certain methods of making new and useful filamentary materials from vegeare more 'abundant- The filamentarymaterials oi modified vegetable globulin produced. in'ac cordance with this invention, arefbetter than those previously available, and are also cheaper.

It is an object achieved by-the present invening after the extraction or expression of oil -from the seeds.

table globulins, and especially from certain-oil seed globulins, including the arachins'oi' thepeanut (Arachis Hypogaea) and other vegetable globulins obtainable from hemp seed (e. g. edestin) and from the castor oil bean. These filafrom protein sources. ,It is. a" further.- object achieved by the invention to facilitate the prep-.

mentary materials, although derived from a purely vegetable source, resemble animal fibers in certain of their physical and chemical properties.

Globulins, as a class, are insoluble in water and strong saline solutions but are soluble in weak saline solutions. Liquids so formed are of no particular utility; but dispersions in solutions 0! urea andof some other organic nitrogen com- 40' pounds have the curious property of, thickening with age, ultimately gelling. After aging they, are viscous enough to permit. extrusion as -a con sistent filament, readily handled. They-canbe processed. to give useiul products or good mechanical strength and not attacked by water or.

I the saline solutions in which the original glob-v ulins dissolve.

globulin product, however, depends toa large ex g ple, theylare readily dissolved by dilute' aqueous I solutions. of :common salt -('sodium 'chloride) so- The character or the modified "dium-sulfite andsodium ,bisuifite i-but'they can be precipitated: from such .solutions' 'by s'atur' It, is another object achieved ,by rthe invention to provide a simplified. and improvedproeess en-.

abling the production of filamentary "materials aratlon of a uniform, homogeneously dispersed viscous solution of aprotein, adapted for the production of artificial filamentsby a'wetspinning process. Other objects: and advantages achieved by this invention will beapparentifrom the following description.

Vegetable globulins such: as those contained in" the mentioned oilseeds arexamphotericproteins I having an 'isoelectric pH- range. of approximately 2 I I 4.4 to 5.1. Dilute solutiohsgfa-numberoi saltsp i acids and alkalis' dissolve theseiglobulinsi fol'm ing thin solutions, but :theyareprecipitatedby increasing the saline concentratiori.- For-exam tent on that, of the original globulin. Th best. 0, products, we find, are given' by oil seed globulins chosen from the class consisting of the globulins of the peanut, the ede stinoi hemp seed and the globulins oi thecastor bean.

Artificial filaments have been Produced heretion of the solutionswithwthe saltion-b acidi'fi cation to the isoelectric region. r;-

The vegetable globulins .usedinthepreseiit in ventlon are generally prepared 'byextraction from suchvegetable material as an oil seed presscake. From this product oil has been removed,

at least to a substantial extent. The globulins are extracted with a suitable aqueous solvent medium, e. g. a dilute alkaline or saline solution, and the solution separated from the residue. Advantageously after clarification, it is treated with an acid or other precipitant. In the case of' saline extracts precipitation 01' the globulins may be assisted by cooling the extracts. When it is desired to obtain the globulins in dry solid form, the wet precipitates are advantageously washed with a volatile organic dehydrating liquid such as alcohol or acetone, after washing with water. Vegetable globulins converted into homogeneous dispersions or solutions in most aqueous liquids are characteristically thin and lack viscosity. -It has not hitherto been possible to prepare continuous artificial filaments by the appli-- cation 01' a wet spinning process to'these solutions or dispersions. We have fond, however, as stated, that if dry or moist globulins are taken up in urea solutions of suitable concentration, a dispersion or solution is formed which is initially thin enough to permit clarification and other purifying operations, but steadily increases in viscosity upon standing at suitable temperatures,

" tmded through .a spinneret into a coagulating finally becoming a Jelly. At a stage of .thicken- -ing prior to the formation of Jelly, the dispersion -bath is a saline solution, prefe bath which is advantageously war or hot. This ly acidified; and the coagulated filaments formed by extrusion into the 1 bath are advantageously drawn through it at a linear rate exceeding the rate of extrusion. The filaments are then subjected, advantageously under tension, to treatment with a hardening agent, such as formaldehyde; and sometimes to other treatments, as hereinafter set 'orth. New and useful filaments are thus obtained.

'lhe time required for the urea solution of the vegetable globulins to become sufliciently viscous may range from several hours to several days, depending on the temperature at which the solution is stored, and on other factors. It is usually advantageous toemploy a temperature enough above atmospheric to accelerate aging. when it is desired to store an aged or matured solution without'furtherviscosity increase, that is, when the aged solution is not to be used imable agitation, the mixture first thickens 'and forms a pasty mass. As the quantity of urea is increased about one part urea for each part of lobulin (calculated on a dry basis) the mixmediately, further rise in viscosity can be inhibited by cooling; say to about 0 C. The rate at which the urea solution matures and becomes ready for spinning may also be modified by the inclusion of asmall amount of one or more substances which may be termed "spinning auxiliaries." These include glyoxal polymer, formaldehyde, ethylene oxide, glycide, salicylic acid, tri'a'cetin, sorbitol, glycerol, polyglycols, glucose, triethanolamine and'thiourea. Various protective colloids or dispersing agents are also use ture becomes non-viscous and assumes the character of a not very viscous solution in which the vegetable globulin is completely dispersed. The

pasty mass initially obtained is useless for spinning, even when diluted with'water; and the thin solution as finally obtained by adding more urea is equally useless. It is a remarkable discovery that these thin completely dispersed solutions of vegetable globulins, and especially oil seed globulins, in aqueous solutions of urea, gradufonate and the like.

ally undergo an increase in viscosity during storage. As noted, this increase in viscosity continues until a jelly is produced, but prior to the Jelly stage, the thickened dispersions pass through stages in which they have a viscosity enabling them to be drawn out into filaments. In accordance with the present invention,- the aged dispersions of vegetable globulins having the desired viscosity characteristics, are extruded through a spinneret into a saline coagulating bath. Coagulated filaments are thus produced ful; these including glue, gelatin, gum arabic, methyl. cellulose, sodium formaldehyde-naphthalen'e sulfonate, sodium propyl-naphthalene sul- Aqueous solutions of urea appear to be the most useful solvents for the vegetable globulins. When in proper concentration, they readily dissolve the protein, bring about rapid denaturation or modification, and exert a strong dispersive action on the modified protein. Other solvents which dissolve and denature vegetable globulins in a similar way are aqueous solutions of thiourea, methyl urea and other. substituted ureas and thioureas, sodium thiocyanate, formamide, acetamide, urethane, and the lower alkyl esters of amino-formic acid. With all of these, it is often advantageous to add protective colloids and dispersing agents, such as those previously mentioned, and to spinning auxiliaries.

The amount of urea or other organic nitrogen compound employed informing the solution of vegetable globulin should be, at least equal to the amount of vegetable globulin for best results and the amount of urea or like solvent and dispersive reagent, when aken with the amount of spinning auxiliary. should be atleast equal to the amount of vegetable globulin. The composition of the solution extruded from the spinneret is advantageously about 15 to 30 per cent. vegetable globulin (calculated on a dry basis), about 15 to 35 per cent. urea, about 10 to 0 per cent. of spinning auxiliary, and about 35 to 60 per cent. water. The globulin mayconveniently be made into a cream with water, and the urea then added, with agitation, either in dry form or include one or more as a strong solution. The optimum time of aging may be readily ascertained by observing, at intervals during the aging of any particular lot of solution, the length and fineness to which a drop taken from the body of solution can be drawn out, either by gravity or between two objects which are readily separated.

In the manufacture of artificial filaments in accordance with this invention, the clarification and deaeration of the protein solution prior to extrusion are operations of great importance. Dirt and mechanical impurities almost inevitably accompany the globulin and remain in the moist or dry preparations. Purification has often been a source of considerable difiiculty heretofore. The present invention has the advantage that these treatments can be effected with relative ease, after the globulin has been brought into dispersion with urea. As noted, the complete dispersion of the vegetable globulin in the urea solution does not immediately result in the formation of a highly viscous solution; and as a result, the solution can be subjected to filtration, centrifuging, reduction of pressure, re-subjection to normal pressure, and like operations, before its viscosity has substantially increased.

After the solution has been purified, and aging has been completed, it is generally desirable to filter the liquor again immediately before extrusion; Extrusion is then effected in an ordinary manner through a submerged spinneret, which may be of the single-hole or multiple-hole type. The orifice or orifices in the spinneret may be of any desired size and shape. Round or elliptical, or solid or tubular filaments may thus be obtained. By using a slot orifice, the material may be obtained in the form of thin sheets or films. v

The coagulating bath .into which the modified vegetable globulin is extruded is ordinarily an aqueous-liquid, such as a salt solution, which is advantageously acidified. The effect of the bath is to counteract suddenly the dispersive effect of the solvent (e. g. urea) on the modified globulin. Suitable saline coagulants for use in the bath include sodium sulfate, ammonium sulfate, sodium sulfite, zinc sulfate and the like. Mineral acids and organic acids may be used to acidify the bath, sulfuric acid and acetic acid being suitable. Salts having an acid reaction, such as acid salts, ammonium salts and zinc chloride, may also be used, with or without neutral salts or acids as adjuncts. Acid materials in the coagulating bath facilitate the production of continuous lengths of good quality filament. The

solutions employed in the coagulating bath are solvents for urea, and terminate its action quickly. The filaments may, however, beacidified with the acid materials after they have been coagulated in a saline bath. The viscosity of the coagulating bath may .be increased, if desired, by the inclusion therein of such materials as gelatin, sorbitol, glycerol, polyglycols, glucose or triacetin. The bath is advantageously maintained at a temperature above 35 C.; a temperature of about 50 C. being generally highly effective.

The filaments coagulated in the bath have a remarkably high extensibility, which is almost completely reversible for extensions up to 100 per cent. and which sometimes amounts to 200 per cent., 300 per cent. or even 600 per cent. With such higher extensions, beyond the elastic limit, the contractile power of the extended filament is correspondingly reduced. Because of the time of all concentrations.

stretch during coagulation, it is generally advantageous to collect them, as by winding on a spool, at a linear rate of about 3 to 6 times the rate of extrusion. I v v p The filaments withdrawn from the coagulating bath are generally too hydrophilic to be directly used for textile purposes. They are also too soluble in dilute solutions ofsodium chloride and certain other salts, for instance they are soluble;

in 10 per cent. sodium chloride solution. In order to improve the physical properties of the filaments, and especially to reduce their extensibility, to increase their tensile strength, and to render them less hydrophilic, they are subjected to treatment with what is here termed a hardening agent. Aqueous solutions of formaldehyde are often most convenient for this purpose, but various other substances are useful hardening agents.

Among these are aluminium salts, chromium salts, chromates and certain phenolic compounds. Aluminium sulfate, chrome alum, potassium bichromate, tannic acid and picrlc acid are useful. Picric acid dyes the filaments yellow and chrome alum generally gives them a gray green colour. Sometimes this effect is wanted.

It is often desirable to remove part or all of the retained coagulating solution from the filaments before the hardening treatment is applied,

effect on the filaments; but nevertheless a further softening treatment of the hardened (formaldehyde treated) filament is often desirable. Suitable treatments for this purpose include brief immersion in a solution of a wax, such as paraflin wax, carnauba wax or candelilla wax, dissolved in oil or in alcohol.

. The hardened filaments of our invention are resistant to cold water and aqueous saline solu- They have good tensile strength, usually ranging from '7 to 9 kilograms per square millimeter section; and an excellent extensibility amounting to about 40 to 60 percent. at break. They also have a soft flexible warm handle. They resemble animal fibers such as wool and silk in certain of their chemical and physical properties, but differ in others. Thus they are resilient, but are not characterised by surface scales and do not tend to felt together. Being produced in continuous filaments,.they can be cut to any desired length and may be manufactured into textile goods, by

increased strength attained as a result of the ordinary methods, such as carding, drafting, combing, gilling, roving, drawing, twisting, warping, weaving and knitting, either alone or with other textile filaments. Mixtures of the globulin fiber with enough wool to enable felting are desirable for some purposes. The fabrics produced from them may be dry cleaned. The filaments resist the action of a scouring bath containing 0.5 per cent. soap and 0.1 per cent. sodium carbonate at 45 for 20 minutes. They can be therefore successfully laundered under quite ordinary laundry conditions. When the filaments of our invention are subjected to suitable after-treatble textile materials.

Because of the differences in properties, it appears that the molecular structure of the protein in the filaments coagulated from the aged viscous solution of the vegetable globulin in concentrated aqueous urea is different from that of the original globulin used for making upthe solution, and from that o powdery precipitates recovered from solutions the globulin in alkaline, saline or unaged urea solutions. It is believed that in the processes leading to the formation of the filament the originally coiled up molecules of the globulin become uncoiled; that the polypeptide chains are more or less extended and grouped into parallel bundles, a change sometimes referred to as denaturation or degeneration. The beneficial efl'ect of the subsequent hardening, if carried out with formaldehyde, may be due to a reduction in the number of free amino groups. The invention, however, does not depend on any such specific theory. The material of which the coagulated but unhardened filaments, whether acidified or not, are composed, is referred to hereinafter as a modified protein derived from a vegetable globulin. The material of which the hardened filaments are composed is also referred to as a, modified protein derived from a vegetable globulin, although as noted it has different properties.

In obtaining vegetable globulins from peanuts, castor beans and other oil seeds for use in accordance with this invention, it is always best to avoid the use of temperatures above about 40 C. since it is undesirable to alter or cook the protein and thus change its properties before it has been extracted and isolated. Oil seeds may be crushed to form a meal and then defatted by extraction with easily volatile oil solvents, such as light .petroleum hydrocarbons, low boiling chlorinated aliphatic hydrocarbons, trichlorethylene and the like. It is advantageous to remove as much of the oil in the defatting process as can conveniently be arranged, and whether an expression process or extraction process is used, it should be conducted without excessive heating of the material. Globulins are extracted from the defatted residue, as by means of a cold dilute alkaline solution, and the solution may be filtered or centrifuged or both, in order to clarify it. Sodium or potassium carbonate, sodium or potassium hydroxide, ammonia, sodium or potassium sulfide, sodium sulfite, lime water or the like may be used. The concentration employed should not be suificient to cause extensive hydrolysis of the globulins; and in the case of the caustic alkalies we have found concentrations of about 1/20th normal to be suitable, the volume of the solution amounting to about 10-20 times the weight of the meal, or more. From the alkaline solution the globulin can be recovered in good yield by carefully acidifying it to the isoelectric region of the globulin; for instance, with sulfuric or sulfurous acid.

After the globulin has been filtered off and washed it may be dried in the air with or without the assistance of neutral volatile organic solvents soluble in water, such as alcohol or acetone.

When so obtained, the globulin usually contains about 10 to 12 per cent. moisture as determined by drying a sample to constant weight at 100 C. The presence of a little residual oil in the globulin may render the urea solution slightly turbid, but

assassa this does not matter; it does not prevent successiul spinning.

The vegetable globulins may be extracted by means of saline solutions instead of alkalies, for instance, with a 2 to 5 per cent. sodium chloride solution. It is sometimes possible to obtain clearer solutions in this manner, especially with a meal which has not been very thoroughly defatted. The introduction into the extract of soap derived from free fatty acids in the oil is also avoided. Th globulin may be recovered from the saline solution by acidification to the isoelectrlc region or by diluting the solution and cooling it to a temperature slightly above the freezing point of the extract. While as stated the globulin is not soluble in water, it often happens that salts are present in the meal to an extent rendering it possible to employ water as an extracting agent. The invention is illustrated but not limited by the following examples, in which the parts are parts by weight.

Example I 35 parts of peanut globulin (containing about 12 per cent. of moisture), parts of crystalline urea, 5 parts of crystalline thiourea and 1 part of sorbltol are ground up to a fine powder in a mortar. 1 part of sheet gelatin, and 0.5 part of glyoxal polymer are dissolved in 78 parts of water. This solution is added slowly with stirring to the powdered mixture, when complete or nearly complete dispersion is readily obtained. The viscous solution thus obtained is filtered and the filtrate centrifuged at high speed to remove air bubbles. The clarified liquor thus obtained is allowed to stand for about 20 hours. During this period the viscosity rapidly rises, and the solution is then ready for spinning. But it is in the best condition for spinning between the second and fifth day following the initial preparation. After this period it may gel.

For spinning the filaments or fibers the ripened solution is passed through a spinneret immersed in a bath containing the following substances:

Parts Ammonium sulfate 15 Zinc chloride 2 Conc. sulfuric acid (98 per cent) 4.5 Glycerine 10 Water 75 The bath is kept at a temperature of about 50 C. and the filaments produced are spun on to a spool placed in such a position that the filaments are drawn through the solution for a distance of about 15 inches. The filaments or fibers from a single, or better, a multiple jet spinncret are produced at a rate of about 130-150 meters a minute. The spool itself rotates above a second bath containing either (1) a solution made by mixing equal volumes of water and glycerol, or (2) an aqueous solution containing 25 per cent. by weight of sorbitol, and is so placed that the fibers or filaments collecting on the spool are continuously bathed in the fluid, which is kept at room temperature.

When a sufiicient quantity of filament has been collected it is removed from the spool and immersed for at least 2 hours in a third bath containing a solution of the same composition as the second, which is also at room temperature. This third bath acts as a softener.

The mass of filament or fiber is then immersed in a fourth bath containing commercial 40 per 75 cent formaldehyde at room temperature for about 18 hours. The filaments or fibers are thereby strengthened. They are then thoroughly washed with water and dried. The quality and appearance of the filaments are further improved by immersion in a softening bath containing an aqueous l' per cent. solution of urea for-ihour ,at room temperature, followed by washing and drying. Enhanced luster is obtained by immersion for 15 minutes in a warm solution of paraffin wax per cent. in olive oil).

Example II 3-4 days. Spin as in Example I with bath of following composition kept at 40.

. Parts Sodium sulfite Glacial acetic acid 5 40 per cent. formaldehyde 2.5

Water 80 The filaments or fibers are collected on a spool at the rate of 70-80 meters per minute. The spool is run in the air or partially immersed in the bath as in Example I. After-treatments are applied as in Example 1.

Example III A peanut cake from which the oil has been removed is extracted with sodium hydroxide of 0.2 per cent. concentration, and the globulins are precipitated by treatment of the centrifuged alkaline extract with sulfur dioxide. 24-25 parts by weight of the air-dry protein (10 per cent. moisture) are thoroughly wetted with 70 parts by weight of water and formed by mechanical action into a smooth paste, to which is added 30 parts by weight of crystalline urea. Mechanical action is continued until the protein is dissolved. The solution is filtered and deaerated while still freshly made. It is then aged for 48 hours at 23 C. after which the viscosity is suflicient to enable it to be used for the preparation of filaments. The solution is extruded through a spinneret into a bath kept at 50 C. containing 100 parts by weight of water, 12.25 parts by weight of commercial salt-cake, and 4.04 parts 98 per cent. sulfuric acid. The material is wound up under tension at a speed of about '70 meters per minute, which is five times the linear rate of extrusion. The fiber is wound into the form of a hank and washed in 50 per cent. glycerine while stretched to maintain its length. While still stretched, it is further treated for 24 hours at room temperature with 40 per cent. formaldehyde solution. The hank is now washed thoroughly in several changes of cold water, wrung out and dried ofi. The filaments of this example are not only resistant to the action of dilute common salt solutions, for instance, of 2 to 5 per cent. concentration, and of cold water, but they may also be treated without damage by agitation in a bath containing 0.5 per cent. soap and 0.1 per cent. sodium carbonate at 45 C. for minutes. After this treatment they may be rinsed in water and dried at a temperature of about 40 to 50 C. and will still retain a desirable handle.

In many preparations of filaments accordin to our invention, by methods of which the above examples are illustrations, we have found the tensile strengths of the air-dry'filamentsto range between 7 and 9 kilograms per square millimeter section,-and the extensibilities to range between 40 and per cent. at break, the filaments having a soft, flexible warm handle and being insoluble in water and common salt solutions of any concentration, and also being resistant to the action of warm dilute alkaline soap solution and warm water. Such filaments can be dried at about 40-50? C. but should notbe boiled with water. g g 1 As many apparently widely different embodiments of the invention can be made without departing from the spirit and scope thereof, it must be understood that the invention is not limited to any specific embodiment except as defined in the appended claims.

What we claim is: I

1. In making textile threads from .globulins, the process which comprises forming a dispersion of modified vegetable globulin in asolution of 'urea, extruding the dispersion into a liquid capable of counteracting the dispersiveeflect of urea, and thereby forming filaments therefrom.

2. The process of claim 1, to which is added the step of treating the filaments with formaldehyde to improve their strength.

3. The process of claim 1, including the step of ripening said dispersion of modified globulin in urea solution by allowing it to stand for several hours before the step of extruding the dispersion to form filaments.

4. The process of claim 1, wherein the modified globulin is peanut globulin.

5. A process for producing artificial filaments, threads and films from vegetable globulins which comprises forming a solution of a modified vegetable globulin, in a. form insoluble in pure water, in an aqueous solution of an organic nitrogen compound selected from the class consisting of ureas and thioureas and their substitution products, formamide, acetamide, sodium thyocyanate, and lower alkyl esters of aminoformic acids, under such conditions that the globulin is dispersed in said solution and is denatured thereby, extruding the solution of dispersed denatured globulin through an orifice to impart the desired shape to the product, into an aqueous salt solution capable of coagulating the extruded protein into a product having useful properties and collecting the coagulated product.

6. The process of claim 5, wherein the modified globulin is peanut globulin.

'7. The process of claim 5, including the step of ripening the globulin solution by allowing it to stand for several hours before said extrusion,

8. The process of claim 5, wherein the aqueous salt solution for coagulating the globulin dispersion contains a small amount of free acid.

9. The process of claim 5, wherein the coalgulated extruded product is collected under tens on.

10. The process of claim 5, to which is added the step of immersing the coagulated product in an aqueous solution of a reagent which increases its mechanical strength.

11. The process of claim 5, to which is adde the step of subjecting the coagulated product to on after-treatment with an aqueous solution of formaldehyde to increase its mechanical strength.

mately 58 per cent. by weight 01' water and squirt ing the solution through an orifice into a coagulating liquid comprising an aqueous solution of ammonium sulfate, zinc chloride, sulfuric acid and glycerol containing about 70 per cent. by weight of water, the filament being collected under slight tension on a suitable carrier.

14. Process according to claim 13 in which the filament is subjected to successive after-treatments (a) in aqueous sorbitol, (b) in aqueous formaldehyde, in a warm solution of paramn wax in olive oil.

15. A process for preparing filamentary material which comprises forming a solution in which a vegetable globulin is completely dispersed in an aqueous medium containing urea, clarifying and deaerating the solution, aging the solution until it has become sufilciently viscous to be drawn out into filaments, and then extruding it into a saline coagulating solution and withdrawing the filaments at a linear rate exceeding the rate of extrusion.

16. The process of claim 15, wherein the coagulating solution is acidified.

17. The process of claim 15, wherein the withdrawn filaments are subsequently washed under tension with a material of such character as to dehydrate the filaments without injuring them.

18. The process of claim 15, wherein'the withdrawn filaments are treated with a hardening agent while under tension.

19. A process for preparing filaments which comprises treating a suspension of a vegetable globulin in water with sufilcient urea. to completely disperse the globulin into solution, aging the solution until its viscosity is increased sufficiently to enable it to be drawn out into filaments and wet spinning it into a coagulating solution.

20. A process for preparing filament which comprises treating a suspension of a vegetable globulin in water with sufilcient urea to completely disperse the globulin into solution, aging the solution until its viscosity is increased sufficiently-to enable it to be drawn out into filaments and wet spinning it into an acidified saline coagulating solution maintained at a temperature substantially above room temperature.

21. The process of claim 19, in which the said suspended and dispersed vegetable globulin is an oil seed globulin which has not been exposed to a temperature of above 40 C. in the course of its preparation.

22. A process for preparing filament which comprises treating a suspension of a vegetable globulin in water with suificient urea to completely disperse the globulin into solution, aging the solution until its viscosity is increased suificiently to enable it to be drawn out into filaments, wet spinning it into a coagulating solu tion and acidifying the resulting filaments.

23. The process of claim 19, in which the said vegetable globulin is derived from peanuts.

24. In a process for preparing filaments from vegetable globulin, the combination of steps which comprises forming a solution'containing about 15 to 30 per cent. oi'the globulin, calculated on a dry basis, about 15 to 35 per cent. of urea, about to 0 per cent. or a spinning auxiliary therein comprising thiourea, and about 35 to 60 per cent water, agitating the mixture until the globulin is completely dispersed. and aging the solution until it can be drawn out into filaments.

25. The process of claim 19, wherein the said solution comprising a vegetable globulin and urea is treated to efiect clarification and deaeration before its viscosity has increased sufilciently to render it capable of being drawn into filaments.

26. In a process for preparing filaments from vegetable globulin by a wet spinning process wherein extruded and coagulated filaments are withdrawn from a coagulating bath at a rate exceeding the rate at which they are extruded, the operation comprising washing the coagulated filament in an aqueous solution of glycerol 01' a concentration operative to dehydrate the filament, and subsequently hardening the filament with formaldehyde while the filament is stretched to maintain its length.

27. In a process for preparing filaments from vegetable globulin, the combination of steps which comprises forming a solution containing about to per cent of the globulin, calculated on a dry basis, about 15 to per cent of urea, and the 1 balance essentially water, agitating the mixture until the globulin is completely dispersed, and aging the solution until it can be drawn out into filaments.

28. A modified protein in filamentary form comprising a modified vegetable globulin coagulated from a dispersion of said globulin in an aqueous solution of an organic nitrogen compound selected from the class consisting of ureas and thioureas and their substitution products. formamids, acetamide, sodium thiocyanate and the lower alkyl esters of amino formic acids, said filamentary material being resistant to the action of a scouring bath containing 0.5% soap and 0.1 percent sodium carbonate at C. for twenty minutes, and insoluble in sodium chloride solutions and water.

29. A modified protein in filamentary form comprising a'vegetable globulin coagulated from a dispersion of said globulin in a solution of urea, and characterized by resistance to the action of a scouring bath containing 0.5 per cent soap and 0.1 per cent sodium carbonate at 45 C. for twenty minutes, said filamentary material being insoluble in sodium chloride solutions and water.

ALBERT CHARLES CHIBNALL. KENNETHBAIIEY, 

